This invention relates to connectors for joining the ends of two lengths of electric cable, such as employed for large diameter cables for carrying very high current which may exceed 1,000 amperes. These single wire connectors are well-known and are often called "welded connectors" simply because, at first, such current transporting cables were joined by electric welding.
The connectors known to the present consist of a male terminal or plug attached to one end of an electric cable and a female terminal or socket attached to the other. Connection is effected by the insertion of the male terminal or plug into the female terminal or socket, and partially rotating one of the terminals so that a bayonet connection on one of the terminals is utilized. This forces a contact surface or frontal face on one terminal into contact with a similar contact surface or frontal face on the other terminal. It is clear, however, that such a connector, which consists only of a plug and a socket held together by a bayonet connection, does not ensure high quality or efficient electrical contact and that any play, slight as it may be, between the contact surfaces produces unacceptable heating, given the high currents employed.
A significant improvement in the quality of the connectors and the contact between the surfaces has been attained by equipping the female terminal with a spring-biased contact surface and providing the bayonet connection with a guide ramp for the plug when inserted in the socket so as to load the spring and thus resiliently urge the two contacts together in the course of the rotational movement of the bayonet connection. There is, however, one difficulty or weakness which arises, particularly where high currents are utilized and that is the movable spring-bias contact has a tendency to heat up and make is generally unacceptable.
Finally, in all the prior art connectors, the simple handling of the connected cable very often involved an accidental unlocking of the bayonet connection and a separation of the terminals. This disconnection occurred more often with larger cable with its greater inertia. As a matter of fact, this shortcoming is so well-known that it is utilized by workmen to effect a quick separation of the terminals without the necessity of taking hold of the connector itself when a line is being dismantled or disconnected.